We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-18 · 7 min read · Independent comparison
If you want featherweight earbuds you can pocket and forget, choose Sony MDRE9LP/BLU; if you need a volume-limited, foldable headphone built for a child, choose EarFun S1. These are two wired 3.5mm audio products, but that is where the similarity ends. One is a tiny open-air earbud aimed at casual adult listening. The other is an on-ear kids' headphone engineered around hearing protection and durability. Pick based on who is wearing them, not on which brand name sounds more familiar.
• Sony MDRE9LP/BLU — biggest strength: genuinely compact, lightweight earbuds with 13.5mm dynamic drivers, an open-air design and an angled 3.5mm plug for everyday portable listening.
• Sony MDRE9LP/BLU — biggest trade-off: it's a bare-bones wired earbud with no volume limiting, no headband, and only a short 90-day seller warranty.
• EarFun S1 — biggest strength: an 85dB volume limit plus a foldable 118g on-ear frame and an 18-month warranty — clearly built for kids and travel.
• EarFun S1 — biggest trade-off: it's an on-ear headphone with a headband, so it's bulkier than earbuds and its whole identity is child-focused, not adult casual listening.
• Who each is for: Sony MDRE9LP/BLU for an adult who wants cheap-and-simple pocket earbuds; EarFun S1 for a parent buying a safe, foldable headphone for a child.
The Sony MDRE9LP/BLU is the definition of a no-fuss earbud. It uses 13.5mm neodymium dynamic drivers in an open-air design, and Sony positions that combination around clear, natural audio with deep bass. The spec sheet lists a 16 ohm impedance and a frequency response up to 22,000 Hz. Low impedance like that means it doesn't demand much from a phone, tablet or laptop headphone jack to reach a usable listening level — which lines up with the claim that it still sounds full even at lower volumes.
The physical design is where this thing earns its place. It's an in-ear, rounded-tip earbud made of plastic, and it ships with two sets of silicone earbuds so you can get a more secure, comfortable fit. The angled 3.5mm plug is a small but real detail: an angled plug puts less strain on the cable right where it meets the connector, which is usually the first place a cheap wired earbud fails. Sony also lists a built-in media control and sound isolation as the noise approach. Total weight is about 22.68g for the package, so this is something you genuinely forget is in your pocket.
Who should buy it? In my opinion, this is for the adult who wants an inexpensive, ultra-light spare pair: keep one in a bag, one at a desk, one in the car. It's also a reasonable pick for anyone who dislikes the clamp of on-ear headphones and prefers tiny buds that sit in the ear. Who should skip it? Anyone buying for a young child, and anyone who wants a volume ceiling. There is no 85dB limiter here — the design assumes an adult controlling their own volume. If you need a headband, foldability or a long warranty, this isn't the product. And since it's an open-air earbud, don't expect the isolation of a sealed headphone; Sony lists sound isolation, but the open design inherently lets more of the room in.
The EarFun S1 is a purpose-built kids' headphone, and every spec points that way. The headline feature is the 85dB volume limit — the headphones are designed so the maximum loudness stays at what's generally treated as a safe level for children, while EarFun says detail is still audible. That single design decision is the reason this product exists, and it's the reason a parent should consider it over a generic pair of adult earbuds.
On sound, EarFun uses larger 40mm dynamic drivers with its own tuning, aiming for distortion-free output with clear mids and highs plus strong bass — enough for online classes, audiobooks, music and video. The listed specs are 32 ohm impedance, 100dB sensitivity and a 20Hz–20,000Hz frequency range. Higher impedance and sensitivity numbers than the Sony mean it's a different electrical load, but both are standard 3.5mm wired devices, so either works with the usual phone, tablet, laptop or PC headphone jack.
The build is the other half of the story. It's an on-ear headphone in a composite enclosure at 118g — noticeably more than the Sony earbuds, but light for a headband model. The 90-degree rotatable, foldable design is the key practical feature: it collapses down for a backpack or school bag. EarFun also describes an adjustable headband and ultra-soft earcaps for a fatigue-free fit, a claimed CPC safety certification, and a gold-plated 3.5mm connector angled at 120 degrees for durability. The warranty is 18 months, which is a meaningful signal of confidence for a kids' product that will get tossed around. Noise control is listed as none, so this is not an isolating headphone — it's an open-ish on-ear.
Who should buy it? Parents and guardians buying for a school-age child: school, travel, tablets, PCs, online learning. Who should skip it? An adult who wants discreet in-ear buds, or anyone who wants maximum portability with nothing on their head. The S1's entire value proposition is child safety and kid-proofing, and if that's not your use case, its main feature is wasted on you.
• Best for young children → EarFun S1. The 85dB limit is the whole point and the Sony has no equivalent.
• Best for ultra-light portability → Sony MDRE9LP/BLU. In-ear buds at roughly 22.68g versus a 118g on-ear headband.
• Best for school and travel with kids → EarFun S1. The 90-degree foldable design and adjustable headband are made for bags and growing heads.
• Best for a cheap spare pair for adults → Sony MDRE9LP/BLU. Simple, tiny, and it comes with spare silicone tips for fit.
• Best warranty coverage → EarFun S1. 18 months versus a 90-day seller warranty on the Sony.
• Best for long listening sessions without ear fatigue → EarFun S1. The soft earcaps and headband spread pressure instead of resting in the ear canal opening.
• Best for fitting in a pocket with your phone → Sony MDRE9LP/BLU. Nothing to fold, nothing to wear on your head.
• Best all-rounder for a mixed household → EarFun S1 for the kids, Sony MDRE9LP/BLU for the adults. Honestly, if you have children, these two don't really compete — they serve different people.
If I had to pick one, I'd buy the EarFun S1 — but only because the scenario where this comparison actually matters is a parent shopping for a child, and the 85dB limit plus the foldable, 118g kid-proof build and 18-month warranty are exactly what that buyer needs. The Sony MDRE9LP/BLU is a fine, honest little earbud, and for an adult who just wants pocket-sized wired buds, I'd recommend it without hesitation. So: buy the S1 for a kid, buy the Sony for yourself. If you're weighing cost, check the current price on Amazon for both before deciding — the value math is yours to run.
Yes, in my opinion. The S1 has an 85dB volume limit, a foldable adjustable headband and an 18-month warranty. The Sony earbud has no volume limiter and a 90-day seller warranty, so it isn't designed with children in mind.
Absolutely. It's a 16 ohm wired in-ear earbud with 13.5mm dynamic drivers, an angled 3.5mm plug and two pairs of silicone tips. It's a sensible, lightweight everyday bud for phones, tablets and laptops.
Yes. Both are wired 3.5mm devices. The Sony uses an angled 3.5mm plug; the EarFun S1 uses a gold-plated 3.5mm connector angled at 120 degrees. Neither is wireless.
Neither is a noise-cancelling product. Sony lists sound isolation for its earbud; EarFun lists no noise control for the S1. If blocking noise matters, don't expect much from either — the S1 is an on-ear kids' headphone, not an isolating one.
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